Decentralized control of ideal ternary reactive distillation column with inert

•Composition measurement based and temperature inferential control structures.•Proposal of three-point composition control structure for the example RD column.•Failure of two point structures due to fixed reflux ratio.•Independent manipulation of reflux rate and distillate is the key. Decentralized control of an ideal hypothetical ternary reactive distillation column with an inert component is explored. Both composition measurement based and temperature inferential control structures are designed using simple heuristic approaches (two and three-point). The three-point composition control structure is proposed for the example RD column for the first time in this work. Although stable closed loop responses are seen for the throughput changes for all, the two-point structures have failed to achieve tight control of the product purity in the bottoms or purity of inert in the distillate for the inert composition changes due to fixed reflux ratio. The performances of the three-point control structures for the inert composition changes are quite satisfactory due to the indirect manipulation of the reflux ratio. The independent manipulation of the reflux rate and distillate (instead of fixed reflux ratio policy) is an important control decision for the successful regulation of the example RD column. [Display omitted]